Compact Refrigerators

Connecting a portable fridge to my car?

hi there i have a few questions, as im wanting to connect up a portable fridge (Waeco or Engel) to run on my car power and when the car is of, i want it to run of a seperate battery. how can i do this? so while the car is running, i want the fridge to run of the cars power. but when stopped, can i connect up a seperate battery system to it to run for the day or two i stopped when traveling cheers

Public Comments

1. go to a caravan dealer and get a Leisure pack it will switch between 2 battery's but be aware you need to get the fridge as cold as you want it before connecting to 12 volt as 12 volt will only keep it at that temperature you can not start from scratch and cool it down on 12 volts
2. You need the second battery, sized to power your refrigerator, for as long the car will not be running. You will need to figure out how much power (watt-hours) it will be using that time, and if it is an AC powered fridge, the loss if the inverter (usually 5%), and the fact you do not use all the capacity of a battery, usually 2/3s to 3/4s of it. You will need a charging isolator, which will charge both batteries from your alternator, or add an alternator to charge the second battery. Doable, but not recommended, is to get a high current battery contactor (such as Ford cars and trucks used to have), to connect the secondary battery to the primary one when the car ignition (and hopefully the engine running) is turned on. In any case the fridge would be get its power from the second battery terminals.
3. your car alternator has a capacity to handle one battery at a time so u need to have two alternator, one for car and second for fridge.